Rotary yarn feeding apparatus in which yarn is wound on a drum have previously been proposed. Usually, a plurality of windings, or loops of the yarn are wound on the drum to form a storage winding. Such drums are driven either individually, or, as is cutomary, may be driven by means of an endless drive belt which, in turn, is driven from the central drive of the machine. The drive belt engages a pulley which is coupled to the storage drum. If the arrangement is to be used with circular knitting machines, then the drive belt is usually common to all the feeds of the machine, the drive belt itself being driven from a central position either separately or from the main drive of the machine, directly, or through an intermediate speed change arrangement. In some constructions, the pulley driving the drum and the drum itself are combined to form one constructional unit in order to save space and decrease the overall size of the yarn feeding apparatus--see, for example, German disclosure document DT-OS Nos. 2 159 154 June 14, 1973.
To provide slip-less feed of the yarn from the drive, it is necessary to place a comparatively large number of loops on the drum so that there is little slip between the yarn and the drum due to the extended frictional engagement formed by the number of loops. As the number of loops or windings on the drum increases, the feed in axial direction of the loops to permit feeding of the yarn from the storage position becomes increasingly complex. Various feed arrangements have been proposed, for example wobble disks or the like which continuously feed the storage windings axially along the drum so that the windings placed on the storage zone will wind evenly and can be removed continuously and with uniform tension.